A large body of research has demonstrated the effectiveness of behavioral interventions in reducing HIV risk in diverse populations. Yet, despite the utility of program replication kits and other science-based HIV prevention resources, the process of implementing evidence-based programs remains challenging for frontline HIV prevention providers, who often have limited knowledge and skills in the areas of program selection, planning, adaptation and evaluation. The HIV/AIDS Prevention Program Replication and Adaptation Online Professional Development Resource (HAPPRA) will address this need by creating a one-stop online resource to support frontline practitioners' replication and adaptation of 10-12 efficacious HIV prevention programs. HAPPRA will combine: (1) digitized replication kits for 10-12 effective HIV/STI prevention programs from Sociometrics' HIV/AIDS Prevention Program Archive (HAPPA) and Program Archive on Sexuality, Health and Adolescence (PASHA); (2) an hour-long interactive, multimedia course on replicating and adapting each included prevention program; (3) four brief (half-hour) multimedia overview courses on the fundamentals of HIV prevention program replication and adaptation, and (4) diverse technical assistance and information exchange modalities, including webinars, live Ask the Expert forums, live-chat technical assistance, a community blog, a practitioner forum, case studies, and FAQs aimed at building a community of practice around the effective programs. Continuing education credits will be offered for each training course through the American Psychological Association (APA), the National Commission for Health Education Credentialing (NCHEC), and the National Association of Social Workers (NASW). This combination of traditional and Web 2.0 capacity building methods meets the call for new strategies to improve the dissemination and utilization of science-based HIV resources and will support a community of practice of HIV prevention practitioners with varied needs, learning styles and technology preferences. Product impacts will be assessed through a fidelity study with 50 community/faith-based organizations to determine if and how access to HAPPRA resources improves implementation fidelity. The creation of this project will (1) expand the dissemination and implementation of proven HIV prevention programs; (2) contribute to greater implementation fidelity in HIV prevention programming, which has been linked to positive HIV risk reduction behavioral outcomes; (3) address the capacity building needs of frontline HIV prevention practitioners in a cost-effective manner; (4) increase our understanding of how practitioners use different technology transfer modalities to translate research into practice; and (5) facilitate th development of a new online community of practice of HIV prevention practitioners.